An accessory dwelling unit is an attached or detached residential dwelling unit which provides complete independent living facilities for one or more persons, and includes separate permanent provisions for entry, living, sleeping, eating, cooking, and sanitation on the same parcel as a single-family dwelling. An accessory dwelling unit may also be provided as an efficiency dwelling unit and/or a manufactured home. (SMC 19.92.020.A)
A junior accessory dwelling unit is a living space not exceeding 500 sq. ft. in size and contained entirely within an existing single-family dwelling. A junior accessory dwelling unit shall include an efficiency kitchen, and may include separate sanitation facilities or share sanitation facilities with the existing structure. (SMC 19.92.020.A)
“Efficiency dwelling unit” means a small, self-contained dwelling unit (occupied by no more than two persons) containing a (only one1) habitable room of not less than 150 square feet of floor area and a minimum horizontal dimension of seven feet. Bathrooms, toilet rooms, closets, halls, storage or utility spaces and similar areas are not considered habitable rooms [The City Planning Department considers “a small, self-contained dwelling unit” to be a dwelling unit not exceeding 850 square feet in floor area.]
“Dwelling unit” defined.
“Dwelling,” “dwelling unit,” or “housing unit” means a room or group of internally connected rooms that have sleeping, cooking, eating, and sanitation facilities, but not more than one kitchen, which constitute an independent housekeeping unit, occupied by or intended for one household on a long-term basis. (SMC 19.92.020.D)
“Efficiency kitchen” defined.
“Efficiency kitchen” means a removable kitchen that contains a sink with a maximum [vertical] waste line diameter of 1.5 inches; appliances that do not require electrical service greater than 120 volts, or natural or propane gas; a limited food preparation counter; and storage cabinets. The entire kitchen shall not exceed six lineal feet, except that if existing counter space is being converted to efficiency kitchen use then the counter space shall not exceed eight lineal feet. [Examples of prohibited cooking appliances are: ranges, stoves, cook tops, and built-in ovens. Examples of cooking appliances that may be used are: microwave ovens, hot plates, and similar appliances intended for use on top of a countertop. Refrigerator size is not limited.]
 See CA Health & Safety Code 17958.1
See the Accessory Dwelling Unit Requirements.